Constructing phase boundary in AgNbO3 antiferroelectrics: pathway simultaneously achieving high energy density and efficiency

Abstract

Dielectric capacitors with high energy storage density (Wrec) and efficiency (η) are in great demand for high/pulsed power electronic systems, but the state-of-the-art lead-free dielectric materials are facing the challenge of increasing one parameter at the cost of the other. Herein, we report that high Wrec of 6.3 J cm-3 with η of 90% can be simultaneously achieved by constructing a room temperature M2–M3 phase boundary in (1-x)AgNbO3-xAgTaO3 solid solution system. The designed material exhibits high energy storage stability over a wide temperature range of 20–150 °C and excellent cycling reliability up to 106 cycles. All these merits achieved in the studied solid solution are attributed to the unique relaxor antiferroelectric features relevant to the local structure heterogeneity and antiferroelectric ordering, being confirmed by scanning transmission electron microscopy and synchrotron X-ray diffraction. This work provides a good paradigm for developing new lead-free dielectrics for high-power energy storage applications.

Large polarization and record-high performance of energy storage induced by a phase change in organic molecular crystals

“…As shown in Figure 6a, the excellent W r of SQA is justified by its best performance with respect to both the maximum polarization P m and the switching field E sw (the average of forward and backward phase switching fields). However, the W r , P m , and E sw values are smaller than those of the bulk antiferroelectric ceramics and their relaxor modifications, [12][13][14][15][16][17][18][19][20][21][22][38][39][40][41][42][43][44] as evident in Figure 6a and 6b. The magnitude relation of the performance is drastically different in Figure 6c, which is a replot of the data against the stored energy density per weight (W r =8 instead of that per unit volume (W r ).…”

Antiferroelectrics: History, fundamentals, crystal chemistry, crystal structures, size effects, and applications

“…247 Recently there has been a resurgence of interest in AgNbO 3 as a high-energy density capacitor material. 248,249 The recoverable energy density (W rec ) is optimized in AgNbO 3 through dopant strategies that delay the onset of the field-induced transition to higher values of E and which also facilitate a slimmer field induced region of the P-E hysteresis loop, as shown in Figure 34. Optimized compositions are typically RE doped on the A site, which gives rise to V′ Ag and are Ta doped on the B site.…”

Achieving ultrahigh energy-storage capability in PbZrO3-based antiferroelectric capacitors based on optimization of property parameters

“…[20][21][22][23] Despite recent research studies carried out on AgNbO 3 (AN)-based and NaNbO 3 (NN)-based lead-free AFE ceramics, they are still not suitable for commercial development in multilayer ceramic capacitors (MLCCs) because of their high cost and complex preparation process. [24][25][26][27][28][29][30] In contrast, PbZrO 3 (PZ)-based ceramics, as typical AFE materials, stand out owing to their wide operating temperature and low cost. Although the pure PbZrO 3 possesses a large P max , the inferior electric eld endurance and low phase switching eld limit the improvement of energy-storage capability.…”